I just received word from an authoritative source on this vulnerability (actually the person that found it) and was informed that version 4.7.2B does not fix the DoS vulnerability. The only way to mitigate the risk is to block TCP port 80 on your concentrator (or upstream router/firewall), otherwise an attacker could send a stream of packets that takes out the concentrator and forces you to power cycle the box to get it back. Ouch.
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Thank you to Eldon Sprickerhoff for pointing this out.

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Paul Asadoorian is the Founder & CEO of Security Weekly, where the flagship show recently re-titled "Paul's Security Weekly" has been airing for over 8 years. By day he is the Product Evangelist for Tenable Network Security. Paul produces and hosts the various shows here at Security Weekly, all dedicated to providing the latest security news, interviews with the industries finest and technical how-to segments. Paul is also the founder and host of "The Stogie Geeks Show", featuring cigar reviews for cigar enthusiasts.